//写cookies 
	function setCookie(name,value) 
	{ 
	    var Days = 90; 
	    var exp = new Date(); 
	    exp.setTime(exp.getTime() + Days*24*60*60*1000); 
	    document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString(); 
	} 
	
	//读取cookies 
	function getCookie(name) 
	{ 
	    var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
	 
	    if(arr=document.cookie.match(reg))
	 
	        return unescape(arr[2]); 
	    else 
	        return null; 
	} 
	
	//删除cookies 
	function delCookie(name) 
	{ 
	    var exp = new Date(); 
	    exp.setTime(exp.getTime() - 1); 
	    var cval=getCookie(name); 
	    if(cval!=null) 
	        document.cookie= name + "="+cval+";expires="+exp.toGMTString(); 
	} 
	
	